This proposal seeks support to complete the analysis of interview data collected in Brazil during 1972-1973. The data consist of three samples: interviews with 269 elites (higher civil servants, senators and deputies, industrialists and financiers, trade union presidents, bishops, and leaders of associations in the liberal professions); a multistage probability sample (n equals 1,314) of the population in six states of the Center-South; and a systematic random sample of 352 trade union members in 12 of the largest unions in Rio and Sao Paulo. The analysis entails the testing of two complementary models of public opinion concerning government policy about birth control. One model is perceptual: it involves a comparison of individual preferences about birth control policy with the policy preferences of groups as perceived by others outside these groups. The joint distribution of individual attitudes and mutual perceptions constitutes the structure of policy preferences. Application of this approach also generates estimates of group behavior which are more accurate than those usually obtained by attempting to predict the behavior of individuals from their own attitudes. The other model involves a belief systems framework. It relates preferences on birth control to preferences on other issues of political importance in order to determine the presence of ideologies. Testing of this model enables us to understand the political context and possible side-effects of various policy alternatives with respect to birth control.